From: Peter Xu <peterx@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v2 8/9] KVM: x86, SVM: isolate vcpu->arch.dr6 from vmcb->save.dr6
Date: Mon, 11 May 2020 12:15:05 -0400 [thread overview]
Message-ID: <20200511161505.GI228260@xz-x1> (raw)
In-Reply-To: <a0dd65bc-bfea-75b8-60d7-5060b9ee6c51@redhat.com>
On Sat, May 09, 2020 at 03:28:44PM +0200, Paolo Bonzini wrote:
> On 08/05/20 17:32, Peter Xu wrote:
> > On Fri, May 08, 2020 at 12:33:57AM +0200, Paolo Bonzini wrote:
> >> On 07/05/20 21:28, Peter Xu wrote:
> >>>> - svm->vcpu.arch.dr6 = dr6;
> >>>> + WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT);
> >>>> + svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM);
> >>>> + svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1;
> >>> I failed to figure out what the above calculation is going to do...
> >>
> >> The calculation is merging the cause of the #DB with the guest DR6.
> >> It's basically the same effect as kvm_deliver_exception_payload.
> >
> > Shall we introduce a helper for both kvm_deliver_exception_payload and here
> > (e.g. kvm_merge_dr6)? Also, wondering whether this could be a bit easier to
> > follow by defining:
>
> It would make sense indeed but I plan to get rid of this in 5.9 (so in
> about a month), as explained in the comment.
OK. I thought it would be easy to change and verify when with the selftests,
however it's definitely ok to work upon it too. Thanks,
--
Peter Xu
next prev parent reply other threads:[~2020-05-11 16:15 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 11:50 [PATCH v2 0/9] KVM_SET_GUEST_DEBUG tests and fixes, DR accessors cleanups Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 1/9] KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 2/9] KVM: x86: fix DR6 delivery for various cases of #DB injection Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 3/9] KVM: X86: Set RTM for DB_VECTOR too for KVM_EXIT_DEBUG Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 4/9] KVM: X86: Fix single-step with KVM_SET_GUEST_DEBUG Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 5/9] KVM: selftests: Add KVM_SET_GUEST_DEBUG test Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 6/9] KVM: nSVM: trap #DB and #BP to userspace if guest debugging is on Paolo Bonzini
2020-05-07 18:22 ` Peter Xu
2020-05-07 11:50 ` [PATCH v2 7/9] KVM: SVM: keep DR6 synchronized with vcpu->arch.dr6 Paolo Bonzini
2020-05-07 18:22 ` Peter Xu
2020-05-07 22:21 ` Paolo Bonzini
2020-05-07 11:50 ` [PATCH v2 8/9] KVM: x86, SVM: isolate vcpu->arch.dr6 from vmcb->save.dr6 Paolo Bonzini
2020-05-07 19:28 ` Peter Xu
2020-05-07 22:33 ` Paolo Bonzini
2020-05-08 15:32 ` Peter Xu
2020-05-09 13:28 ` Paolo Bonzini
2020-05-11 16:15 ` Peter Xu [this message]
2020-05-07 11:50 ` [PATCH 9/9] KVM: VMX: pass correct DR6 for GD userspace exit Paolo Bonzini
2020-05-07 16:18 ` Peter Xu
2020-05-07 16:21 ` Paolo Bonzini
2020-05-07 16:38 ` Peter Xu
2020-05-07 17:42 ` Paolo Bonzini
2020-05-07 18:05 ` Peter Xu
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